Filters

ABSTRACT

A filter is disclosed which comprises a housing ( 46.1 ) having an inlet ( 48.1 ) and an outlet ( 50.1 ) and a filter cartridge ( 44.1 ) having a core ( 54.1 ). A float ( 56.1 ) in the core ( 54.1 ) has a buoyancy such that it sinks in the liquid product to be filtered and floats in a liquid which contaminates the liquid product. A seat ( 52.1 ) is provided at the upper end of the core ( 54.1 ) so that, as the level of contaminant liquid in the housing ( 46.1 ) increases, the float ( 56.1 ) rises in the core ( 54.1 ) and presses against the seat ( 52.1 ) to isolate the inlet ( 48.1 ) from the outlet ( 50.1 ) and thus flow through the filter is terminated. A drain outlet is provided at the lower end of the housing ( 46.1 ) and comprises a chamber ( 68 ) and a seat ( 62 ) against which a sealing element is pressed by a spring ( 66 ). The chamber ( 68 ) is connected to the outlet ( 50.1 ) by a pipe ( 70 ). Pressing of a vacuum release button ( 76 ) opens the chamber ( 68 ) to the atmosphere which creates a suction effect that overcomes the force of the spring ( 66 ) and allows the seat ( 64 ) to move downwards allowing liquid contaminant to exit the housing ( 46.1 ) via the pipe ( 70 ) and outlet ( 50.1 ).

FIELD OF THE INVENTION

THIS INVENTION relates to filters.

BACKGROUND TO THE INVENTION

Filters are used in the fuel lines of diesel and petrol engines. Thefilters are intended to remove contaminants such as water and solidparticles. Current technology is resulting in high volume fuel flowrates, particularly in diesel engines, with the consequence that filtersin use at this time are, at least in circumstances where an exceptionallevel of contamination occurs, unable to prevent the contaminant passingthrough the filter. This can cause engine damage.

The high level of fuel flow rate in a diesel engine is because the fuelis used to cool the fuel injectors. Thus most of the fuel pumped isreturned to the tank and only a relatively small percentage of thatpumped is consumed in the engine.

The present invention seeks to provide an improved filter for removingcontaminants, both solid and liquid, from a flowing fluid product. Thefluid product will normally be fuel flowing to an engine but can beanother liquid product or a gas which must be delivered free of solidand liquid contaminants.

With the ever-increasing awareness of the impact of substances andcontaminants on the environment, the present invention further seeks toprovide means for removing the contaminants from the fuel and disposingof the contaminants in an environmentally-friendly way and withoutallowing the contaminants to flow out of the filter and onto the road.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the present invention there is provided afilter for removing contaminants from a flowing fluid product comprisinga housing having an inlet and an outlet, a filter cartridge in thehousing, means for mounting the cartridge in the housing, and means forrotating the cartridge.

Said means for rotating the cartridge can be blades over which flowingfluid product passes and which apply a torque to the cartridge.Alternatively the means can be a nozzle or a series of tangentiallyarranged nozzles from which the fluid product flows, the reaction forceas the fluid product leaves the nozzle(s) causing the cartridge torotate.

According to a further aspect of the present invention there is provideda filter for removing contaminants from a flowing liquid productcomprising a housing having an inlet and an outlet, a filter cartridgehaving a core, a float in the core, said float having a buoyancy suchthat it sinks in the liquid product to be filtered and floats in aliquid which contaminates said liquid product, and a seat against whichthe float presses when it floats upwards with an increasing level ofcontaminant liquid in the housing, contact between said float and seatisolating said inlet from the outlet and terminating flow through thefilter.

According to another aspect of the invention there is provided a filterfor removing fluid contaminants from a flowing liquid product comprisinga housing having an inlet and an outlet, a filter cartridge in thehousing, the cartridge having a hollow core, means for mounting thecartridge in the housing, means for rotating the cartridge, a float inthe core, said float having a buoyancy such that it sinks in the liquidproduct to be filtered and floats in a liquid which contaminates saidliquid product, and a seat against which the float presses when itfloats upwards with an increasing level of liquid contaminant in thehousing, contact between said float and seat isolating said inlet fromthe outlet and terminating flow through the filter.

Said float, upon contacting the seat, preferably seals off the outletfrom the interior of the housing.

According to yet another aspect of the present invention there isprovided a filter cartridge for removing contaminants from a flowingliquid product comprising a hollow core, filter material surrounding thecore and a float which can move vertically in the core.

According to a still further aspect of the present invention there isprovided a filter cartridge for removing contaminants from a flowingfluid product comprising a hollow core, a plurality of curved vanesextending outwardly from the core, each vane having a convex leadingsurface and a concave trailing surface and filter material packed intothe depressions defined by said trailing surfaces.

The cartridge defined in the preceding paragraph can include meanswhich, when subjected to fluid product flowing through the cartridge,produces a reaction force for rotating the cartridge. It may alsoinclude a float in the hollow core.

According to yet another aspect of the present invention there isprovided a filter for removing contaminants from a flowing liquidproduct comprising a housing having a main inlet and a main outlet, afilter cartridge in the housing, a first float which sinks in the liquidproduct flowing through the housing but floats in the liquidcontaminant, a first seat, said first float lifting into contact withsaid first seat and closing said main outlet as liquid contaminantaccumulates in the housing, a drain outlet at the lower end of thehousing, a valve closure element, a second seat, spring means forpressing said valve closure element into contact with said second seatthereby to close the drain outlet, a chamber, a connection between saidchamber and the main outlet on the side of the first seat remote fromsaid first float whereby suction is applied to said chamber, suctionapplied to said chamber exerting a force on said element to separates itfrom said second seat, and a second float which sinks in the liquidproduct flowing through the housing but floats in the liquidcontaminant, said second float, when in its sunken position, closing offsaid drain outlet.

According to still further aspect of the present invention there isprovided a filter for removing contaminants from a flowing liquidproduct, said filter comprising a housing having a main inlet and a mainoutlet, a filter cartridge in the housing, the cartridge having a hollowcore which is open at both its upper end and its lower end and filtermaterial sheathing the core, a float which sinks in the liquid productflowing through the housing but floats in liquid contaminant, said floatbeing in said hollow core, a seat, said float lifting into contact withsaid seat and closing said main outlet as liquid contaminant accumulatesin the housing, filter material across the open lower end of the corethrough which liquid contaminant can flow into said core, flow of liquidcontaminant through said filter material across said open lower end ofthe core occurring, in use, at a faster flow rate than the flow ofliquid contaminant through the filter material sheathing the core

According to yet another aspect of the present invention there isprovided a filter for removing liquid contaminants from a flowing liquidproduct, and including absorbent material located on the underside ofsaid housing, liquid contaminant and solid contaminants discharged fromthe housing, in use, flowing into said absorbent material, the liquidcontaminant evaporating therefrom into the atmosphere.

The filter defined in the preceding paragraph can include a holder forsaid absorbent material, said holder having openings for permitting airto flow into the holder.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show how thesame may be carried into effect, reference will now be made, by way ofexample, to the accompanying drawings in which:—

FIG. 1 is a diametral section through a filter;

FIG. 2 is a horizontal section through the filter of FIG. 1;

FIG. 3 is a section through another filter;

FIG. 4 is a section through a further filter;

FIG. 5 is a section through the upper portion of a still further filter;and

FIG. 6 is a pictorial view of a portion of the lower end of the casingof a filter and showing an evaporator.

DETAILED DESCRIPTION OF THE DRAWINGS

The filter 10 illustrated in FIGS. 1 and 2 comprises a cylindricalhousing 12 having an inlet 14 for contaminated fluid product and anoutlet 16 for filtered fluid product. Within the housing 10 there is afilter cartridge 18.

The cartridge includes a tubular core 20, the core having a plurality ofholes 22 in the walling thereof; Filtered product enters the core 20through these holes 22. A plurality of curved vanes 24 (see FIG. 2)extend outwardly from the core 20.

Each vane 24 has a convex leading face 26 and a concave trailing face28. The concave faces 28 define depressions into which filter material32 is packed. The filter material used currently in fuel filters is apaper which is folded to provide a series of layers, and this type offilter material can be packed into the depressions.

The core 20 is extended in each direction by spigots 34, 36. Thesespigots run in bearings 38, 40 carried by the housing 12. The spigot 36carries a plurality of blades 42 over which the filtered product flowingfrom the core 20 to the outlet 16 passes. The blades 42 are soorientated that the flowing product produces a reaction force whichrotates the cartridge 18 in the bearings 38, 40.

The blades 42 can be replaced by a nozzle which is directed tangentiallywith respect to the axis of rotation of the cartridge. Fuel flowing fromthe nozzle causes a reaction force which rotates the cartridge. Two ormore nozzles can be used.

The blades 42 or nozzle(s) can be carried by the cartridge.Alternatively they can be carried by a rotatable part of the housing andthere can be means for rendering the cartridge fast with the rotatablepart of the housing.

In use contaminated product enters the housing 12 via the inlet 14 andflows into the cartridge 18. After passing through the filter medium thefiltered product flows into the core 20, through the spigot 36 and thusreaches the outlet 16. The product flowing over the blades 42 causes thecartridge 18 to rotate in the bearings 38, 40.

The concave front surfaces of the vanes 24 throw solid contaminantsoutwardly towards the housing's cylindrical wall thus keeping them fromthe filter material 32 behind the vanes:

The vanes 24 can be inclined so that, in the direction of rotation, theupper part of the vane leads the lower part. This imparts a downwardcomponent to the force applied to the solid particles thus assisting inaccumulating them in the lower part of the housing.

The housing 12 can have a manually operated drain or an automaticdrainage system as illustrated in FIG. 4 etc.

The fluid product which flows through the filter of FIGS. 1 and 2 isnormally a liquid in which event the contaminant removed comprises solidparticles. However, the fluid product can be a gas in which event thecontaminant removed can be a solid or a liquid.

Turning now to FIG. 3, the cartridge 44 illustrated is within a housing46 having a contaminated liquid product inlet 48 and a filtered liquidproduct outlet 50. The cartridge 44 has a perforated core 54 with afloat 56 in the core. The float 56 has a buoyancy such that it sinks inthe liquid to be filtered but floats in the liquid contaminant. Normallythe liquid to be filtered is diesel or petrol (gasoline) and thecontaminant water and solid particles.

The outlet 50 is encircled by a valve seat 52. As the level of the waterremoved from the contaminated product rises, the float 56 floatsupwardly in the core 54. Eventually the float 56 is pressed against theseat 52 thus preventing water retained in the housing 46 from leavingthe housing via the outlet 50 and reaching the engine.

The rotary filter of FIGS. 1 and 2 can be provided with a float asdescribed with reference to FIG. 3, and the filter of FIG. 3 can beprovided with a manually operable drain or with an automated drainagesystem as illustrated in FIG. 4 etc. The cartridges 18 and 44 can bedisposable.

The housing 12 can have a manually operated drain tap or can have anautomatic water dumping system such as is described hereinafter withreference to FIG. 4.

Referring now to FIG. 4, this shows a further form of filter. Whereapplicable like-parts have been designated with the same referencenumerals as used in FIG. 3 with the addition of the suffix .1.

The lower end of the core 54.1 is constituted by an annular end plate 55which bounds a central opening 57. There is, below the open lower end ofthe core 54.1, a disc 58 which is held in place by a holder 60.

At the lower end of the housing 46.1 there is a drainage outletcomprising a valve seat 62, a valve closure element 64 and a coil spring66 which normally presses the element 64 against the seat 62.

The spring 66 is in a chamber 68 which is connected by a pipe 70 to theoutlet 50.1. The element 64 is constituted by a flexible diaphragmforming part of the wall of the chamber 68. Thus suction at the outlet50.1 is applied to the chamber 68 thereby to suck the element 64 awayfrom the seat 62.

A cage 72 is provided above the seat 62, there being a float 74 in thecage 72. The float 74 co-operates with a valve seat 73.

A vacuum release button 76 is provided for connecting the inlet 50.1 toatmosphere and allowing air to flow in.

The fuel entering through the inlet 48.1 is usually contaminated withwater. The fuel passes through the filter cartridge 44.1 and exitsthrough the outlet 50.1. The removed water accumulates in the bottom ofthe housing 46.1 and initially causes the float 74 to lift away from thevalve seat 73 so that only the element 64 pressed onto the seat 62 bythe spring 66 prevents liquid from flowing out. Because there is littlein the way of vacuum applied to the chamber 68, the spring 66 is able tohold the element 64 against the seat 62 and thus the water drainageoutlet remains closed.

As the water level rises, the float 56.1 moves upwardly into contactwith the seat 52.1 and flow of fuel through the filter to the engineceases.

It will be understood that fuel being sucked through the filter pullsthe disc 58 against the lower end of the cartridge 44.1 and closes offthe lower end of the core 54.1.

Once flow through the filter is interrupted by the float 56.1, thesuction effect in the outlet 50.1 is greatly increased and this isapplied through the pipe 70 to the chamber 68. The suction effect issuch that the downward force exerted on the element 64 overcomes theupward force of the spring 66 and the drainage opening at the lower endof the housing 46.1 thus opens. The water level in the housing commencesto drop as drainage takes place through the drainage outlet.

As soon as flow through the filter ceased, the element 58 dropped awayfrom the lower end of the core 54.1. Hence water is able to flow fromthe core 54.1 around the element 58 and out through the drainage outlet.

As the water level approaches the lower end of the housing 46.1, thesinking float 74 abuts the seat 73 and seals-off the drainage outletbefore fuel can emerge. The element 64, however, remains spaced from theseat 62 in view of the fact that the float 56.1 is still sucked againstthe seat 52.1, and the vacuum condition has not been broken.

When the vacuum release button 76 is pressed, air flows into the outlet50.1. The float 56.1 is thus no longer sucked against the seat 52.1 andit drops back to the bottom of the core 54.1. Simultaneously thesub-atmospheric pressure in the chamber 68 increases and the spring 66is able to overcome the vacuum derived force. The element 64 thusre-seats and the drainage outlet is closed.

In a modified form the reset button 76 is omitted and the float 56.1 hasa bore through it from top to bottom. When the float 56.1 lifts intoengagement with the seat 52.1, the engine draws a vacuum in the outlet50.1 before fuel starvation shuts it down. Depending on the size of thebore in the float, fuel flows at a predetermined rate through the floatand the vacuum condition is relieved. By adjusting the size of the bore,the time for which the drainage outlet is held open can be adjusted. Afilter of this type is fully automatic and does not require driverintervention to restart flow of fuel.

Referring now to FIG. 5, a still further form of filter is shown. Whereapplicable, like-parts have been designated with the same referencenumerals as used in FIGS. 3 and 4 with the addition of the suffix 0.2.

An opening 57.2 at the lower end of the core 54.2 is smaller in FIG. 5than it is in FIG. 4. Below the opening 57.2 there is filter material 80in the form of a screen or membrane. A drainage outlet, as illustratedin FIG. 4, but not shown in FIG. 5, is provided at the lower end of thehousing 46.2 and connects to the outlet 50.2 via a pipe 70.2.

Fuel entering through the inlet 48.2 is usually contaminated with water.The fuel passes through the filter cartridge 44.2 and exits through theoutlet 50.2. The removed water accumulates in the bottom of the housing46.2.

The resistance to fluid flow through the filter material 80 is lowerthan through the filter cartridge 44.2. Therefore, as the water level inthe housing 46.2 rises to the bottom of the filter cartridge 44.2, thewater is first drawn into the core 54.2 through the filter material 80via the opening 57.2. The water flowing into the core 54.2 via theopening 57.2 causes the float 56.2 to lift prior to water being drawninto the core 54.2 through the filter cartridge 44.2. This ensures thatthe float 56.2 is rising above the level of the water that is ingressinginto the core 54.2 through the filter cartridge 44.2. This situationprevents any water from exiting the filter cartridge 44.2 via the outlet50.2 prior to the float 56.2 engaging the seat 52.2.

As the water level rises, the float 56.2 moves upwardly into contactwith the seat 52.2 and flow of fuel through the filter cartridge 44.2 tothe engine ceases.

The removal of liquid contaminant from the filter of FIG. 5 is the sameas described above in relation to the filter of FIG. 4.

Referring now to FIG. 6, an evaporator, generally designated 82, isfitted to the lower end of the housing 46.2. The evaporator 82 comprisesa holder 84 which contains absorbent material 86. The holder 84 hasopenings (not shown) in it which permit air to flow over and through theabsorbent material 86. The evaporator 82 is fitted by means of a clip orbolts (not shown), or any other suitable attachment means.

Water and other contaminants in liquid form are absorbed by the material86 during manual or automatic drainage. Any solid contaminants areentrained within the material 86. Airflow over the absorbent material 86as well as through the absorbent material 86, allows the removed liquidcontaminants to evaporate into the atmosphere.

The evaporator 82 thus allows for the removal of contaminants from thefuel, without disposing of the contaminants onto the road surface.

1. A filter for removing contaminants from a flowing fluid product, saidfilter comprising a housing having an inlet and an outlet, a filtercartridge in the housing, means for mounting the cartridge in thehousing, and means for rotating the cartridge.
 2. A filter as claimed inclaim 1, wherein said means for rotating the cartridge comprises bladesover which the fluid product passes and which apply a torque to thecartridge.
 3. A filter as claimed in claim 1, wherein said means forrotating the cartridge is a nozzle from which the fluid product flows,the reaction force as the fluid product leaves the nozzle causing thecartridge to rotate.
 4. A filter as claimed in claim 1, wherein saidmeans for rotating the cartridge is a series of tangentially arrangednozzles from which the fluid product flows, the reaction force as thefluid product leaves the nozzles causing the cartridge to rotate.
 5. Afilter for removing contaminants from a flowing liquid product, saidfilter comprising a housing having an inlet and an outlet, a filtercartridge having a core, a float in the core, said float having abuoyancy such that it sinks in the liquid product to be filtered andfloats in a liquid which contaminates said liquid product, and a seatagainst which the float presses when it floats upwards with anincreasing level of contaminant liquid in the housing, contact betweensaid float and seat isolating said inlet from the outlet and terminatingflow through the filter.
 6. A filter for removing contaminants from aflowing liquid product, said filter comprising a housing having an inletand an outlet, a filter cartridge in the housing, the cartridge having ahollow core, means for mounting the cartridge in the housing, means forrotating the cartridge, a float in the core, said float having abuoyancy such that it sinks in the liquid product to be filtered andfloats in a liquid which contaminates said liquid product, and a seatagainst which the float presses when it floats upwards with anincreasing level of liquid contaminant in the housing, contact betweensaid float and seat isolating said inlet from the outlet and terminatingflow through the filter.
 7. A filter as claimed in claims 5 or 6,wherein said float, upon contacting the seat, seals off the outlet fromthe interior of the housing.
 8. A filter cartridge for removingcontaminants from a flowing liquid product, said filter cartridgecomprising a hollow core, filter material surrounding the core and afloat which can move vertically in the core.
 9. A filter cartridge forremoving contaminants from a flowing fluid product, said filtercartridge comprising a hollow core, a plurality of curved vanesextending outwardly from the core, each vane having a convex leadingsurface and a concave trailing surface and filter material packed intothe depressions defined by said trailing surfaces.
 10. A filtercartridge as claimed in claim 9 and including means which, whensubjected to fluid product flowing through the cartridge, produces areaction force for rotating the cartridge.
 11. A filter cartridge asclaimed in claims 9 or 10, and including a float in the hollow core. 12.A filter for removing contaminants from a flowing liquid product, saidfilter comprising a housing having a main inlet and a main outlet, afilter cartridge in the housing, a first float which sinks in the liquidproduct flowing through the housing but floats in the liquidcontaminant, a first seat, said first float lifting into contact withsaid first seat and closing said main outlet as liquid contaminantaccumulates in the housing, a drain outlet at the lower end of thehousing, a valve closure element, a second seat, spring means forpressing said valve closure element into contact with said second seatthereby to close the drain outlet, a chamber, a connection between saidchamber and the main outlet on the side of the first seat remote fromsaid first float whereby suction is applied to said chamber, suctionapplied to said chamber exerting a force on said element to separate itfrom said second seat, and a second float which sinks in the liquidproduct flowing through the housing but floats in the liquidcontaminant, said second float, when in its sunken position, closing offsaid drain outlet.
 13. A filter for removing contaminants from a flowingliquid product, said filter comprising a housing having a main inlet anda main outlet, a filter cartridge in the housing, the cartridge having ahollow core which is open at both its upper end and its lower end andfilter material sheathing the core, a float which sinks in the liquidproduct flowing through the housing but floats in liquid contaminant,said float being in said hollow core, a seat, said float lifting intocontact with said seat and closing said main outlet as liquidcontaminant accumulates in the housing, filter material across the openlower end of the core through which liquid contaminant can flow intosaid core, flow of liquid contaminant through said filter materialacross said open lower end of the core occurring, in use, at a fasterflow rate than the flow of liquid contaminant through the filtermaterial sheathing the core.
 14. A filter as claimed in any one ofclaims 1 to 7, 12 and 13, and including absorbent material located onthe underside of said housing, liquid contaminant and solid contaminantsdischarged from the housing, in use, flowing into said absorbentmaterial, the liquid contaminant evaporating therefrom into theatmosphere.
 15. A filter as claimed in claim 14, and including a holderfor said absorbent material, said holder having openings for permittingair to flow into the holder.